HERAB

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HERA-B
Bernhard Schmidt DESY - HH
PRC open session, October 30, 2002
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Status of run 2000 analysis
- nearing completion
?
?
submitted
in press
Some additional theses ongoing
There are no more data left to analyze
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Detector status
?
?
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ITR

• HV training completed (425 hours operation),
  stability ok
• HV problems 4 (160) chambers in-operational (1
  cathode, 3 GEM) acceptable level
• Hit efficiency (90 - 95) S/N (16-24) looks
  ok
• Alignment first iterationdone

chambers of MS01 layer
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ITR-2
25 of channels show no signal !

• New problem observed recently

normal chamber
abnormal chamber
REASON UNCLEAR
Run 19990
ITR-tracks at exit of PC section
Due to high redundancy in ITR Coverage and
efficiency of trackingstill sufficient
Worrisome but not fatal
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OTR

• Fully operational in trigger and for tracking
• HV problems level out mean time between
  failures at 58 h (since May 2002)
• Noise level improved considerably

threshold, noise at 1
Channel statistics
(-)
()
Cell efficiency gt95 ,fine for triggering and
tracking
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ECAL
Calibration precision

• Fully operational and calibrated with ?? (1)
• Dramatically improved performance compared to
  2000( noise, stability, spatial resolution)

1
8
ECAL-2
J/??ee signals
-1? lt E/p lt 3?

• improved PID with ECAL
• no BR tag required to see J/?

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Muon System

• Operational, some non-working chambers in MU1,
  not critical
• No new HV problems since May 2002
• Efficiency of pad read out on average 883
  (include. dead channels), no major holes

Not perfect, but sufficient for triggering
Muon tracks at MU1 position
J/y-gtµµ online
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TRIGGER and DAQ status FLT

• FLT routinely used for J/y triggering now
• High level of understanding but still some
  mysteries
• single track efficiencies usable (25 µ-ons, 60
  for electrons )
• FLT - pair trigger works

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trigger schemes

• No FLT-pairs, but FLT(1 track 1 pre-trigger)
  SLT(2tracks)

star mode

• advantage
• much less affected by FLT efficiency (OR inst.
  AND)
• covers ITR for second track (acceptance at xFgt
  0)

achieved J/? rates
400 J/? per hour and MHz interaction rate (eµ)
? Dead time, achievable interaction rate ?
gt 800 J/? per hour
Typical 30 DT at 3 MHz Seen 0 DT at 3 MHz
-gt ?
work ongoing
beam DAQ conditions
We hope to get 1000 J/? per hour these days.
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Status of Commissioning
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• running in 2002 so far

70
Many thanks to HERA for giving us beam in hard
times
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Readiness for data taking

• Spectrometer performance

Carbon target 7106 events
With RICH PID.
Statistics KS 90200 ? 20000 ? 9700
Counts
Mass (GeV/c2)
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Readiness

• Spectrometer considerably improved since 2002

• Performance and reliability of sub-detectors
• Calibration and alignment
• Reconstruction algorithms
• Data Quality Monitoring
• ..

Track finding efficiency (real data) 2000 86.9
2.3 2002 96.5 2.0
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Readiness..

• J/? trigger (signals, rates)

J/?
mm
?
Collection rate
1000 J/psi per real hour (both channels) almost
at hand
ee
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Physics goals Run plans
The initial goal for 2002

• Measurement of the b cross section
• Publishable charmonium physics
• Investigation of physics program beyond 2002

2106 J/y?????months running
We Are Ready To Take These Data
- complicated situation with HERA planned new
shutdown-
we need SERIOUS physics data before shutdown
OR collaboration will collapse
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Physics goal run plan - present planning

• Reduced time scale 52 days stable running
• with existing performance
• lower limit for meaningful charmonium program and
  B-cross section measurement
• Mandatory prerequisite stable and reliable HERA
  operation (moderate currents, no aggressive
  machine experiments..)
• Run schedule 75 charmonium prod. 25
  min.bias, calibration, tests..

1/6 of planned data sample
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Perspectives and Outlook

• HERA-B in better shape than ever
• Ready to take serious physics data NOW

We need these data